1 water quality monitoring through implementation of water safety plan dr a gunasekar who country...
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Water Quality Monitoring Water Quality Monitoring
through implementation of through implementation of
Water Safety PlanWater Safety Plan
Dr A Gunasekar WHO Country Office for India
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Current situation and challengesCurrent situation and challenges
• 88% of India’s population is using improved drinking 88% of India’s population is using improved drinking water sources. (Urban – 96%; Rural – 84%); however water sources. (Urban – 96%; Rural – 84%); however water delivered at the taps may not always be safe to water delivered at the taps may not always be safe to drinkdrinkSource: World Health Statistics, 2011Source: World Health Statistics, 2011
• Diarrhoea is the 2Diarrhoea is the 2ndnd leading cause of death among leading cause of death among children; About 4 lakh children die in India due to children; About 4 lakh children die in India due to diarrhoea every year, that is one child dies due to diarrhoea every year, that is one child dies due to diarrhoea every 80 seconds diarrhoea every 80 seconds Source: Diarrhoea: Why children are still dying and what can be done, Source: Diarrhoea: Why children are still dying and what can be done, UNICEF/ WHO, 2009UNICEF/ WHO, 2009
• 88% of diarrhoeas can be prevented by safe water, 88% of diarrhoeas can be prevented by safe water, sanitation and good hygienesanitation and good hygiene
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WHO Guidelines for Drinking water WHO Guidelines for Drinking water quality - Water Safety Plansquality - Water Safety Plans
The most effective means of consistently
ensuring the safety of a drinking-water
supply is through the use of a comprehensive
risk assessment and risk management
approach that encompasses all steps in
water supply from catchment to
consumer.
The approach is called Water Safety Plan
(WSP)
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What is a Water Safety Plan?What is a Water Safety Plan?
• A documented plan that:A documented plan that:– Identifies Identifies hazards, assesses risks from hazards, assesses risks from
catchmentcatchment to consumer to consumer– PrioritizesPrioritizes risks – with focus on highest risks risks – with focus on highest risks– MitigatesMitigates risks through control measuresrisks through control measures
• Moving away from reliance on output monitoringMoving away from reliance on output monitoring - - i.e. measuring parameters in final wateri.e. measuring parameters in final water
• Move into input monitoringMove into input monitoring - i.e. measuring - i.e. measuring parameters which show that the system is workingparameters which show that the system is working
Consumer system
Distribution system
Water resources &
sourcesTreatment
Hazard, Hazardous event & Risk
• Hazard is a biological, chemical, physical or radiological agent that has the potential to cause harm
• Hazardous event is an incident or situation that can lead to the risk - what can happen and how? (e.g. heavy rainfall)
• Hazard identification - Desk studies & Site visits
• Risk is the likelihood of hazards causing harm in exposed populations including– Specified time frame– Magnitude of the harm – deaths, disease, financial cost
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Why do we need WSPs?Why do we need WSPs?
Hazard (contaminant)
Salmonella
Hazardous event (cause)
Pigeons nesting on a water tank roof
Tank roof was not sealed and pigeon faeces were washed into the tank
Salmonella bacteria got concentrated in the sediment & the surface
During a flushing event, the bacteria got rapidly drained into the distribution system and chlorine residual was not enough
Effect
~ 500 ill from a town of 1,104
7 Dead
Gideon, Missouri, 1993Gideon, Missouri, 1993
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Why do we need WSPs?Why do we need WSPs?
Milwaukee, Wisconsin, 1993• Hazard (contaminant)Hazard (contaminant)
– CryptosporidiumCryptosporidium cysts cysts
• Hazardous event (cause)Hazardous event (cause)– Runoff from heavy spring rains Runoff from heavy spring rains – Carrying sewage into Lake Michigan Carrying sewage into Lake Michigan
(from which raw water was drawn)(from which raw water was drawn)– Coagulation problems on the filtration Coagulation problems on the filtration
system in the water treatment plantsystem in the water treatment plant
• EffectEffect– 400,000 became ill from 1.2 million400,000 became ill from 1.2 million– 100 dead100 dead
Source: Presentation of Mr Asoka Jayaratne, Water Quality SpecialistYarra Valley Water,Melbourne, Australia
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Why do we need WSPs?Why do we need WSPs?
Hazard (contaminants)Hazard (contaminants)E. coliE. coli O157:H7 O157:H7 Campylobacter jejuniCampylobacter jejuni
Hazardous event (cause)Hazardous event (cause) Heavy rainsHeavy rains Cow manure washed into a wellCow manure washed into a well Failure to chlorinateFailure to chlorinate Water supplied by local water utilityWater supplied by local water utility
EffectEffect– 2,300 ill 2,300 ill – 7 Dead7 Dead
Walkerton, Ontario, 2000
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Why do we need WSPs?Why do we need WSPs?
• Recontamination in the Recontamination in the distribution lines and at the distribution lines and at the household levelhousehold level
Components of WSP (1/3)
1. A system assessment to
determine whether drinking-water
supply chain as a whole can deliver
water of a quality that meets
requirements.
Components of WSP (2/3)
Identifying control measures in the system that
will control identified risks and ensure that the
health-based requirements are met.
For each identified control measure, an
appropriate means of operational monitoring
should be defined that will ensure that any
deviation from required performance is rapidly
detected.
Components of WSP (3/3)
Management and communication plans
describe actions to be taken during normal
operation or incident conditions and documenting
the system assessment, including upgrade and
improvement planning, monitoring and
communication plans.
Step-by-step risk management1. Assemble the WSP team
2. Describe the water supply system
3. Identify hazards and hazardous events and assess the risks
4. Determine and validate control measures, reassess and prioritize the risks
5. Develop, implement and maintain an improvement/upgrade plan
6. Define monitoring of the control measures
7. Verify the effectiveness of the WSP
8. Prepare management procedures
9. Develop supporting programmes
10. Plan and carry out periodic review of the WSP
11. Revise the WSP following an incident
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In simple terms, WSP means:In simple terms, WSP means:
Continuous Cycle
1. What are the risks?
1. What are the risks?
3. How do we know the risks
are under control?
3. How do we know the risks
are under control?
2. How do wecontrol the
risks?
2. How do wecontrol the
risks?
Describe the water supply system
• Source of water
• Changes due to weather
• Details of land use in the catchment
• Water storage
• Water treatment (processes and chemicals)
• Storage, distribution network
• Availability of trained staff
• Quality of documentation
Risk assessmentLikelihood Score
• Almost certain (once a day) - 5
• Likely (once a week) - 4
• Moderate (once a month) - 3
• Unlikely (once a year) - 2
• Rare (once every 5 years) - 1
Severity Score
• Insignificant / No impact - 1
• Minor compliance impact - 2
• Moderate aesthetic impact - 3
• Major regulatory impact - 4
• Catastrophic Public Health impact - 5
Likelihood score x Severity score = Risk score
Verify the effectiveness of the WSPTreatment works• pH - Daily• Chlorine dosing records - Weekly• Residual Chlorine - Daily• Turbidity - Daily
Distribution system• pH - Weekly• Chlorine levels - Weekly• Turbidity - Weekly• Sanitary inspection - Weekly
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Why do we need WSPs now?Why do we need WSPs now?
• Increasing risks of water quality – Increasing risks of water quality – microbiological as well as chemicals from microbiological as well as chemicals from industrial and agricultural activities (pesticides industrial and agricultural activities (pesticides and fertilizers) and fertilizers)
• Increased awareness among consumers on the Increased awareness among consumers on the need to have safe waterneed to have safe water
• Outbreaks (in many countries) - due to Outbreaks (in many countries) - due to (re)contamination of water, after treatment(re)contamination of water, after treatment
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Status of WSP implementationStatus of WSP implementation
• WSP piloted in over 40 urban and 100 rural WSP piloted in over 40 urban and 100 rural supplies in Asia - Bangladesh, Bhutan and Nepalsupplies in Asia - Bangladesh, Bhutan and Nepal
• WSP piloted in Hyderabad and Nagpur municipal WSP piloted in Hyderabad and Nagpur municipal water supplies in Indiawater supplies in India
2020
Outcomes of WSP:Outcomes of WSP:Improved water qualityImproved water quality
• Water source protection and preservationWater source protection and preservation
• Small problems are identified early and fixed, Small problems are identified early and fixed,
preventing bigger problems preventing bigger problems
• In water systems where WSP is carried on a In water systems where WSP is carried on a
continuous basis (24 x 7), water is found to be continuous basis (24 x 7), water is found to be
safer to drink with microbiological test results, safer to drink with microbiological test results,
before and after WSP, showing dramatic before and after WSP, showing dramatic
improvementimprovement
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Outcomes of WSP: Outcomes of WSP: improved managementimproved management
• Standard operating procedures improvedStandard operating procedures improved
• Clear roles and responsibilitiesClear roles and responsibilities
• Regular monitoring of water quality in treatment Regular monitoring of water quality in treatment plantsplants
• Promotes conversion to 24x7 supplyPromotes conversion to 24x7 supply
• Reduction in non-revenue waterReduction in non-revenue water
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ConclusionConclusion
• Water safety plan ensures water safety Water safety plan ensures water safety (improves health) and sustainability of (improves health) and sustainability of drinking water suppliesdrinking water supplies
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Thank youThank you